1. Field of the Invention
The present invention relates to a lens barrel which enables a lens group to move in an optical axis direction.
2. Description of the Related Art
In imaging apparatuses such as a digital camera, a lens barrel has been known in which a cam follower is provided on a peripheral surface of a lens retaining member for retaining a lens group, and is inserted into a cam groove provided on a peripheral surface of a rotary barrel. This lens barrel is configured such that the lens retaining member, that is, the lens group held therein, is moved in a photographing optical axis direction by rotation of the rotary barrel by use of guiding action of the cam follower effected by the cam groove. In such a lens barrel, it is known that accuracy of position of the lens group is improved by providing an elastic member between two lens retaining members each of which retains a different lens group, and applying force of the elastic member to press the rotary barrel in the photographing optical axis direction to each lens retaining member, thereby eliminating looseness between the cam follower and the cam groove (eliminating backlash). Here, in the lens barrel, it is desirable to prevent an excessive pushing force from being applied to both lens retaining members, because the force to press in the photographing optical axis direction acts on the rotary barrel having the cam groove into which the cam follower of the lens retaining member is inserted, as rotating load to prevent rotation thereof.
Thus, in the lens barrel, it is considered that a lens retaining member located at an end, of three lens retaining members arranged in the photographing optical axis direction, is configured as a common spring support, and an elastic member is provided between the common spring support and each of the remaining two lens retaining members (see Japanese Patent Application Publication No. 2006-071844). The lens barrel of this configuration enables a stable pushing force to be applied to each lens retaining member, while preventing an excessive pushing force from being applied thereto.